The Eastern Penan language is spoken by approximately ten thousand people in the Malaysian state of Sarawak on the Island of Borneo. This work is the first attempt to fully describe the language.

The Penan Dictionary is a project that I embarked on in 1994. It is a continuing effort, and every year I gather more data in the field and enlarge, refine, and correct my text. As of 2010 I have accumulated more than ten thousand entries, each of which describes a word taken in one of its senses, or a fully-fledged idiom. In addition, there are about six thousand collocations (i.e. idiomatic or semi-idiomatic combinations). The text of the dictionary proper, which includes numerous examples, consists of approximately eight hundred thousand words.

In addition to the dictionary, I have created an English - Penan index, as well as a basic grammar of the language.

This is a new kind of dictionary, making use as it does of some of the formalisms of a lexicographic model known as the Explanatory-Combinatorial dictionary. It is above all a production dictionary, that is a tool that assists its user to produce well-formed texts of the Penan language, rather than just interpret existing texts.

The dictionary remains a work in progress. However, beginning in about 1996 I have been making available copies of the latest version of my manuscript to various interested persons.